I daily'd my 73 240z with original motor, no ac, no working air, no radio, broken original seats, blown rear struts, leaking water in the rain, and cabin exhaust fumes that had been sitting for years before I got it every day putting some days almost 200 miles on it out in the middle of no where in 95+ degree weather and never did it let me down. I did have to replace some very old parts that failed / needed servicing but nothing major and nothing that left me on the side of the road.
Drove it for 8 months straight as my only car before I got a jeep and decided to tear it apart and fix her up.